The study adds to the long list of racial disparities already
known to exist in colorectal cancer incidence, screening and
treatment. And it confirms that many patients of any race
still aren’t receiving appropriate post-surgery radiation
therapy.

Cancer
of the colon and rectum is the fourth most common form
of cancer in the United States, and the second leading cause
of cancer death. More than 135,000 Americans are expected
to be diagnosed with colorectal cancer this year. Although
incidence and mortality rates of colorectal cancer in the
United States are declining, the rate of decline for African-Americans
is slower than for whites.

The new study finds that African-Americans with rectal cancer
were diagnosed at a younger age than whites, and were more
likely to have reached an advanced stage of cancer progression
before their cancer was caught.

They were also more likely than whites to have a kind of
surgery that removes the bowel sphincter, meaning that they
would have to wear a waste-collecting colostomy bag for the
rest of their lives.

African-Americans were also less likely than whites to get
radiation
before or after surgery. But in fact, only half of patients
received such radiation, no matter what their race —
despite the fact that radiation after surgery has been proven
to help survival.

“What we saw is that many people aren’t getting
optimal care, and that some groups are getting even less optimal
care than others,” says Arden Morris, M.D., MPH, a colorectal
surgeon in the U-M Division of General Surgery and Comprehensive
Cancer Center. “We need further studies to understand
these differences, and to guide efforts to improve care through
broader adherence to treatment guidelines.”

Morris began the study while she was a Robert Wood Johnson
scholar at the University of Washington, using the Surveillance
Epidemiology and End Results (SEER) cancer database.
She and her colleagues examined surgery and radiation treatment
patterns for 52,864 rectal cancer patients — 3,851 of
them black — who were treated between 1988 and 1999.
The SEER database includes 11 cancer registries and represents
14 percent of the U.S. population.

The study focused on rectal cancer patients, whose tumors
occur in the last 8 to 10 inches of the large intestine. These
patients have different treatment options than those whose
cancer starts higher up, in the six-foot expanse of the colon.

One major difference is that rectal cancer patients whose
cancer has spread to nearby tissue or lymph nodes often have
surgery near the sphincter, or muscle, that controls the exit
of the bowels. The operation removes the cancerous area and
nearby lymph nodes.

Many surgeons, especially those who operate on many rectal
cancer patients each year, have learned to operate in this
area without removing the sphincter and leaving patients in
need of a colostomy bag.

But the study showed that a higher percentage of whites than
blacks had this kind of sphincter-sparing surgery, while blacks
were 42 percent more likely than whites to have sphincter-ablating
procedures called abdominoperineal resection.

Previous studies have shown poorer self-image and quality
of life for patients whose surgery leaves them in need of
a permanent colostomy, which can inhibit their social and
sexual activity.

Another racial gap was seen in the use of adjuvant radiation
therapy — a series of radiation doses aimed at the cancerous
area from outside or inside the body. Fifty-six percent of
African Americans received no radiation after surgery, compared
to 53 percent of whites — an odds ratio of 30 percent.

“The fact that only half of all patients received radiation,
when it has been recommended as the standard of post-surgical
care for more than a decade, is quite concerning,” says
Morris. “We don’t know where the system is breaking
down but we obviously need to do a better job of diffusing
the evidence-based treatment guidelines that have been developed
for rectal cancer.”

Morris and her colleagues also found that only 7 percent
of patients had radiation before their operation, an approach
known as neoadjuvant therapy that aims to shrink the tumor
and therefore the area affected by surgery. As this treatment
plan increases in use, she hopes future analyses can show
whether race-based gaps in treatment are narrowing.

Overall, Morris notes that colorectal surgeons might take
a page from the playbook of cardiac surgeons, who have implemented
effective nationwide strategies for measuring and improving
the quality of surgical care. And, she calls for further studies
to get to the bottom of why there are such gaps between what
is recommended and what is carried out — for all patients.

“The SEER data do not allow us to see what kind of
role economics, geography, hospital system, surgeon experience
or referral patterns have on the rates of sphincter-sparing
surgery and adjuvant radiation, but further research should
help ascertain that,” she notes. “In the meantime,
it would be easy but wrong to blame these disparities on individual
doctors. This is a problem with our medical system. It deserves
attention and it can be fixed.”

In addition to Morris, the research team includes Nancy Baxter,
M.D., Ph.D., of the University of Minnesota, and Kevin Billingsley,
M.D., and Laura-Mae Baldwin, M.D., MPH, of the University
of Washington. The study was partially supported by the Robert
Wood Johnson Foundation.

For more information on colorectal cancer treatment and surgery
at the U-M Comprehensive Cancer Center, call the Cancer AnswerLine™
at 1-800-865-1125 or visit them on-line.